Overloading generic proc on typedesc causes C compilation to fail

[bluenote10]

I guess the following problem is caused by overloading a generic proc on typedesc:

type
  OptionKind = enum
    None,
    Some

  Option*[T] = object
    case kind: OptionKind
    of None:
      discard
    of Some:
      value*: T

proc none*[T](): Option[T] =
  Option[T](kind: None)

proc none*(T: typedesc): Option[T] = none[T]()


proc test(): Option[int] =
  int.none

echo test()

This results in the following error regarding the C compilation:

/tmp/tmp.9fZIF9AH68/stdlib_system.c: In function ‘HEX24_90091’:
/tmp/tmp.9fZIF9AH68/stdlib_system.c:11193:22: error: expected identifier before ‘)’ token
   if (!(((2 &(1<<((x.)&7)))!=0))) raiseFieldError(((NimStringDesc*) &TMP145));

Version: devel c82cc7c

[jyapayne]

Looks like this has something to do with echoing the result (not sure how you would echo a discard statement).

If you put a $ proc with instructions on how to print the Option object, it compiles and runs fine.

type
  OptionKind = enum
    None,
    Some

  Option*[T] = object
    case kind: OptionKind
    of None:
      discard
    of Some:
      value*: T

proc `$`[T](opt: Option[T]): string =
    return $opt.kind

proc none*[T](): Option[T] =
  Option[T](kind: None)

proc none*(T: typedesc): Option[T] = none[T]()


proc test(): Option[int] =
  int.none

echo test()

[bluenote10]

That's interesting. In my actual implementation I do have a $ proc, and (as far as I remember) I did not echo an Option, but I still get the error. So it looks like the error can somehow come back. I do not even have to call the none(typedesc) proc, just having it defined causes a problem. What is also interesting is that the error is not "in function" none but always in a function that is close by. For instance, I have this:

proc some*[T](value: T): Option[T] =
  Option[T](kind: Some, value: value)

proc none*[T](): Option[T] =
  Option[T](kind: None)

proc none*(T: typedesc): Option[T] = none[T]()

And get the error for the "some" function:

.../nimcache/option.c: In function ‘some_765109’:
.../nimcache/option.c:656:24: error: expected identifier before ‘)’ token
  if (!(((2 &(1<<((LOC1.)&7)))!=0))) raiseFieldError(((NimStringDesc*) &TMP687));

Another surprise: If I reverse the order of the some and none functions, it works! Update: No, error came back, depending on use on client side...